摘要:
Method for the aluminothermic welding of rails, involving the steps of:—triggering an aluminothermic reaction in a crucible,—pouring the metal resulting from said reaction into the mould so as to fill the moulding cavity from the rail flange,—after filling the cavity, triggering a second aluminothermic reaction above the rail head, and pouring the metal resulting from said reaction into the cavity in the region of the rail head. The mould used in the method is designed to fit over the ends of two rails to form a moulding cavity comprising a crucible positioned above the rail head region so that it can be fed with molten metal of the cavity via a secondary passage.
摘要:
A method and apparatus for heating railroad rails enabling a convenient and efficient expansion of railroad rails is provided by selectively moving a heat source along a rail. The apparatus includes a frame carrying a heat source such as a series of gas fired burners which direct heat toward the rail to raise the temperature of the rail. The rail heater is provided with a set of wheels enabling the heater to be rolled along a rail while heating the rail. The wheels are mounted to subframes which are shiftably mounted to the frame to permit the heater to conform to the gauge of the rail on which it travels.
摘要:
Method for the aluminothermic welding of rails, involving the steps of: —triggering an aluminothermic reaction in a crucible, —pouring the metal resulting from said reaction into the mold so as to fill the molding cavity from the rail flange, —after filling the cavity, triggering a second aluminothermic reaction above the rail head, and pouring the metal resulting from said reaction into the cavity in the region of the rail head. The mold used in the method is designed to fit over the ends of two rails to form a molding cavity comprising a crucible positioned above the rail head region so that it can be fed with molten metal of the cavity via a secondary passage.
摘要:
The invention provides a method of cooling a rail weld zone. The method includes a first rail web portion cooling process of cooling a rail web portion cooling region of the rail weld zone in a part of a temperature range until the completion of transformation from austenite to pearlite, a second rail web portion cooling process of cooling the rail web portion cooling region after the entire rail web portion of the rail weld zone is transformed to pearlite, a foot portion cooling process of cooling a foot portion of the rail weld zone, and a head portion cooling process of cooling a head portion of the rail weld zone. When cooling time of the first and second rail web portion cooling processes is t minute, a k value satisfies an expression represented as −0.1t+0.63≦k≦−0.1t+2.33.
摘要:
1,136,356. Welding rails by fusion. ELECTRO-THERMIT G.m.b.H. 16 March, 1966 [6 April, 1965], No. 11578/66. Headings B3R and B3V. [Also in Division C7] In order to improve the strength, particularly the fatigue threshold, of rail welds a residual stress distribution which counteracts the load stress deflexion is obtained either by cooling the rail web more slowly than the head and/or foot subsequent to welding, or by locally reheating the weld in the web region. In the former method the mould material may be removed from the head and foot immediately the metal is solid but allowed to remain on the web until the latter has completely cooled, while in the alternative the web may be reheated by burners or induction heaters but preferably by a pack of exothermic material, the quantity of the latter being selected to provide the desired heat input.
摘要:
The invention provides a method of cooling a rail weld zone. The method includes a first rail web portion cooling process of cooling a rail web portion cooling region of the rail weld zone in a part of a temperature range until the completion of transformation from austenite to pearlite, a second rail web portion cooling process of cooling the rail web portion cooling region after the entire rail web portion of the rail weld zone is transformed to pearlite, a foot portion cooling process of cooling a foot portion of the rail weld zone, and a head portion cooling process of cooling a head portion of the rail weld zone. When cooling time of the first and second rail web portion cooling processes is t minute, a k value satisfies an expression represented as −0.1t+0.63≦k≦−0.1t+2.33.
摘要:
In laying track rails from a continuously moving train which supports continuous lengths of butt-welded rails and whence the rails are placed on successive ties as the train moves forward, successive rail sections are subjected to heating or cooling while they are placed on the ties and before they are secured thereto, to impart to these rail sections immediately adjacent the point at which they are secured a temperature approximately equal to the median or average yearly ambient temperature.